31890473 has 2 divisors, whose sum is σ = 31890474. Its totient is φ = 31890472.

The previous prime is 31890407. The next prime is 31890479. The reversal of 31890473 is 37409813.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25725184 + 6165289 = 5072^2 + 2483^2 .

It is a cyclic number.

It is not a de Polignac number, because 31890473 - 2⁸ = 31890217 is a prime.

It is equal to p_1967471 and since 31890473 and 1967471 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (31890479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15945236 + 15945237.

It is an arithmetic number, because the mean of its divisors is an integer number (15945237).

Almost surely, 2^31890473 is an apocalyptic number.

It is an amenable number.

31890473 is a deficient number, since it is larger than the sum of its proper divisors (1).

31890473 is an equidigital number, since it uses as much as digits as its factorization.

31890473 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 31890473 is about 5647.1650409741. The cubic root of 31890473 is about 317.1175811962.

The spelling of 31890473 in words is "thirty-one million, eight hundred ninety thousand, four hundred seventy-three".